A personal area network is formed when capability addressable network devices communicate meaningfully in a peer-to-peer fashion. The networking occurs spontaneously and with no overt action by the user when the devices come into proximity. The networking takes place between unforeseen devices, that is to say, for any given device it is not predictable which devices will be networked with it at any given instant in time. Capability addressable network functionality can be built into many electronic devices, some of which may be carried on a person, and a person may wander about during the course of a day. As the person carrying, for example, a first device, coupled to a personal area network, comes into range of a second, decoupled device, the second device becomes coupled into the individual's personal area network, and as the person leaves the range of the second device, the second device becomes decoupled again. These very fluid network couplings are established and broken many times throughout the course of the day.
Capability addressable network devices have broad requirements with regard to security issues. In some cases it is necessary to restrict usage of a device to authorized parties. In other cases, resources that a device offers can and should be freely shared amongst any device in proximity. For example, an office would typically have one printer intended to be shared with almost any passerby; the printer or other device should accommodate this sharing will little or no overt action from a user. On the other hand, an individual may carry out financial transactions from a digital wallet, and therefore access to that resource must be private and authenticated. The coupling mechanism must accommodate completely secure systems at one end of the spectrum and readily shareable systems at the other end of the spectrum; the challenge is to prescribe a low interaction mechanism for positioning to any point within that spectrum. The challenge is compounded with the knowledge that the configuration of a personal area network is not static; it dynamically changes as devices move in and out of range.